Shares in the Australian group building the Wembley football stadium plunged to a record low yesterday after it warned it would make a £45 million loss on the project.

Construction firm Multiplex saw its stock hit a low of A$2.27 (94p), before closing slightly higher at 2.56 Australian dollars (107p) - wiping about a fifth off its market value at the end of trading.

In an announcement made in Sydney late on Monday, the group revealed the project would be completed three months later than expected in March, but insisted it would still be ready in time for next May's FA Cup Final.

Multiplex had been forced to suspend its shares on Friday, following its revelation that the loss could be more than double the £21 million the Roberts family, which holds a 26 per cent stake in it, had agreed to cover.

It spent the weekend reviewing the contract before coming up with its estimated loss of around £45 million.

Multiplex warned in February that it expected only to break even on the job after a change in steel contractor led to higher costs and litigation.

Revealing yesterday that it had been forced to make a A$59 million Australian dollars (£25m) write-down on Wembley, the group said there were still several major risks to the project.

These included its ability to recover claims against third parties, costs associated with completing the steel work and the weather.

Multiplex is involved in a number of projects in the UK, including a site in Stratford, east London, which could become the home of the 2012 Olympic village if the London bid is successful.

Earlier this month it made profits of £10 million after selling its 12.5 per cent stake in the White City shopping centre development in London.